FIG. 4 shows an apparatus for X-ray fluoroscopy, including an X-ray imaging system 60 and control system 59. The imaging system 60 has a table 40 for resting a person thereon. A X-ray tube 23 is disposed under the table 40. An X-ray imaging part includes an operation panel 25, a snap shot device 16, an image intensifier 15, and a TV camera 14.
The X-ray tube 23 and the X-ray imaging part are linked by a supporting column 24 and they travel as one united body. The X-ray tube 23 and the X-ray imaging part are movable in the Y axis direction 18, along the person""s length, and also the X axis direction 17, along the person""s width. These movements are carried out by manual operation or motor drive through operation of a handle 47. The X-ray imaging part is also designed to be movable in the Z axis direction 19, up and down with respect to the person. Enlargement fluoroscopy is carried out by adjusting the X-ray imaging part along the Z axis direction.
The operation panel 25 has various switches. Operation of some of these switches makes it possible to move the table 40, by motor drive in the Y axis direction 21 and the X axis direction 20, independently of the movement of the X-ray imaging part. Since the X-ray imaging part and table 40 are movable independently of each other, it is possible to place the center of the X-ray imaging part at a region of concern in the person. The X-ray imaging system 60 is also designed to incline by using switches on the operation panel 25 so that the person on the table 40 is held at a position between the horizontal position and the standing position.
The adjacent operation apparatus has a monitor 46 near the X-ray imaging system 60. When performing X-ray fluoroscopy using this apparatus, under irradiation of weak X-rays, an operator grasps the handle 47 to move the X-ray imaging system 60 first. The operator moves the table 40 and places the center of the X-ray imaging part at a region of concern of the person while watching an X-ray image on the monitor 46. Then, a radiography of the region of concern is carried out by pushing an imaging switch 48.
The control system 59 controls an X-ray high voltage generator 41 according to X-ray parameters preset ahead. When the X-ray high voltage generator 41 provides the X-ray tube 23 with high voltage, the X-ray tube 23 irradiates X-ray. The X-ray transmitted through the person is detected and also changed into a visible image by the image intensifier 15. The TV camera 14 converts the visible image output by the image intensifier 15 into video signals. An A/D converter 42 converts the video signals into digital signals. An image processor 43 carries out image processing of the digital signals to obtain a proper X-ray image. Output data of the image processor 43 are stored in the memory 45. The output data are also converted by a D/A converter 44 into analog signals and then provided to the monitor 46 and a TV monitor 26 of the control system 59 to show an X-ray image thereon.
In case that angiography of a relatively wide range, such as a blood vessel in a leg part, is carried out by using the above mentioned X-ray fluoroscopy apparatus, the X-ray imaging part is moved, thorough use of the handle 47, to track a blood stream (typically contrasted by a contrast medium). Radiography of the blood stream is carried out while tracking the blood stream by using the switch 48. When angiography of a large person is carried out, since it is necessary to have the X-ray imaging part travel for about one meter, an X-ray imaging system which has the X-ray imaging part travel for a long distance is needed. However, the entire structure of the X-ray imaging system becomes very large when the X-ray imaging part is able to travel for a long distance.
In case of carrying out angiography of the whole body or a leg part, it is necessary to have the table 40 travel at velocity faster than the flow of blood; intermittent X-ray irradiation is repeated, having the table 40 move intermittently to get a target blood stream live image. However, this requires a high powered motor able to move the table to chase the X-ray imaging part, which is expensive.
It is therefore desirable to provide an apparatus for X-ray fluoroscopy and a method of angiography which carries out angiography over a wide range without making the apparatus large. It is also desirable to provide an apparatus for X-ray fluoroscopy and a method of angiography which make it possible to chase contrasted blood flow very easily.